There are numerous synonyms for the phrase "a cold fish," which refers to someone who is emotionally distant or unapproachable. Some possible alternatives include "an aloof person," "an unfeeling individual," "a detached personality," or "a cool customer." Other options might include describing someone as "emotionally frigid," "unresponsive," or "uncommunicative." Regardless of the specific words used, the connotation remains the same: a person who is difficult to connect with on an emotional level and who may be distant or unapproachable in certain situations. These synonyms can be useful for writers, speakers, or conversationalists looking to describe someone in this way in a more creative or varied manner.